Locking and disfiguring mechanism for an iontophoretic system

ABSTRACT

An iontophoretic system including a controller and a patch is provided. The controller has a receiving portion including an upper surface and a lower surface, and a member protruding from the lower surface in a ramp-like fashion toward the upper surface and terminating in a top edge near the upper surface. The patch has an interconnection tab including an opening for engaging the protruding member of the controller when the interconnection tab is inserted into the receiving portion of the controller and the opening falls over the top edge of the protruding member.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a locking and disfiguring mechanism for aniontophoretic system including a patch and a controller.

2. Description of Related Art

Iontophoresis is the migration of ions when an electrical current ispassed through a solution containing an ionized species, usually theionic form of a drug or other therapeutic agent (hereinafter referred toas the "drug"). One particularly advantageous application ofiontophoresis is the noninvasive transdermal delivery of ionized drugsinto a patient. Iontophoretic drug delivery offers an alternative andeffective method of drug delivery over other methods such as passivetransdermal patches, needle injection, and oral ingestion, and is anespecially effective method for children, the bedridden and the elderly.

Drug delivery via iontophoresis is done by applying current toelectrodes of an iontophoretic patch. The current is usually suppliedfrom a controller connected to the patch. The electrodes arerespectively arranged within a drug reservoir, containing the drug ions,and a return reservoir, containing an electrolyte. When the patch isplaced on the skin of a patient and the controller is turned on, thecurrent applied to the electrodes forces the drug ions contained in thedrug reservoir through the patient's skin and into the patient'sbloodstream.

The controller usually contains an energy source, for example, abattery, as well as electrical circuitry for generating and regulatingthe current applied to the patch electrodes. Preferably, the controlleris to be reused until its battery dies, while the patch is to be usedonly once to deliver a full drug dosage and then disposed.

The controller and patch may be connected together via aninterconnection tab integral to the patch. This connection is (1)electrical--electrical interconnect leads and terminals connect theelectrodes to the current regulating circuitry; and (2) mechanical--thetab is physically engaged in the controller housing. A problem in thisconnection may arise, however, if the interconnection tab can be easilyremoved from the controller housing during operation of the system. Thiswill cause the patch to separate, either wholly or partially, from thecontroller, which in turn causes the patch to disconnect electricallyfrom the controller. Without an electrical connection, drug delivery tothe patient will cease, and the patient will receive only a partial drugdosage.

Another problem that may arise is the reuse, by the patient or healthcare provider, of a partially-used or spent patch. This reuse may beaccidental or may be purposeful, but should be avoided. Not only isreusing a patch unsanitary, but will most likely result in the deliveryof only a partial drug dosage.

SUMMARY OF THE INVENTION

The present invention advantageously provides a locking mechanism toensure, the mechanical and electrical connection between a patch and acontroller.

The present invention also advantageously provides means for feedingback to the user an increasing tactile resistance when the patch isinserted into the controller, and a mild "snap" when the patch is fullyengaged.

The present invention also advantageously provides a mechanism fordisfiguring or deforming the patch upon its removal from the controllerto prevent its subsequent reuse by the patient or health care provider.

In one aspect of the present invention, an iontophoretic system isprovided including a controller and a patch. The controller includes aportion for receiving the patch. This receiving portion has a protrudingmember which ramps from the front lower surface of the receivingportion, towards the rear of the receiving portion, so that its top edgeis near the upper surface of the receiving portion. The patch includesan interconnection tab having an opening. When the interconnection tabis inserted into the receiving portion of the controller, the openingrises over the top edge of the protruding member and engages theprotruding member, thus locking the patch to the controller.

In another aspect of the present invention, a method for rendering apatch unreusable is provided. An interconnection tab of the patch isinserted into a controller so that the opening of the interconnectiontab engages a protruding member of a receiving portion of thecontroller. When the patch is removed from the receiving portion of thecontroller, either by squeezing and pulling the patch or by pulling thepatch against a cutting edge of the protruding member, theinterconnection tab is permanently disfigured. This prevents itsre-engagement onto the protruding member of the controller, thuspreventing its reuse.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention canbest be understood by reference to the detailed description of thepreferred embodiments set forth below taken in conjunction with thedrawings, in which:

FIG. 1 is a perspective view of an iontophoretic system illustrating afirst embodiment of the present invention.

FIG. 2 is a perspective view of a controller illustrating the secondembodiment of the present invention.

FIG. 3A is a sectional view of the upper surface of the receivingportion of a controller illustrating the second embodiment of thepresent invention.

FIG. 3B is a sectional view of the receiving portion of a controllerillustrating the second embodiment of the present invention.

FIG. 4 is a perspective view of a controller illustrating the thirdembodiment of the present invention.

FIG. 5A is an end view of the controller of the first embodiment of thepresent invention.

FIG. 5B is an end view of the controller of the second embodiment of thepresent invention.

FIG. 6 is a top view of an iontophoretic system illustrating a fourthembodiment of the present invention.

FIG. 7 is a sectional view of the controller of the fourth embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The first embodiment of the present invention relates to aniontophoretic system including a patch 40 and a controller 20, asillustrated in FIG. 1. The controller 20 includes an outer casing whichhouses the energy source and current regulation circuitry required fordriving current into the patch 40. The casing of the controller 20 maybe made of a plastic, metal or other suitable material for encasing andprotecting the current regulating circuitry.

In the first embodiment, the controller 20 includes a receiving portion110, located substantially in the front and center of the controller 20,between a first edge 15 and a second edge 25 of the controller 20. Thelocation of the receiving portion 110 in the controller 20 is notlimited, however, to the front and center and may be located at otherpositions about the controller 20. The controller 20 includes a lowerprotruding member 10, which is located substantially in the center ofthe receiving portion 110 between a first side 70 and a second side 75of the receiving portion 110, and arises from a lower surface 5 of thereceiving portion 110. The controller 20 may also include one or moreupper protruding members descending from an upper surface 22 of thereceiving portion 110, which will be described in more detail below inconnection with a second embodiment. The location of the lowerprotruding member 10 is not limited to the center of the receivingportion 110 and may be located at other positions within the receivingportion 110.

The lower protruding member 10 may slant angularly, in a rampingfashion, so as to rise from the lower surface 5 and terminate near theupper surface 22 of the receiving portion 110. This configuration of thelower protruding member 10 within receiving portion 110 advantageouslyfeeds back to the user an increasing tactile resistance when the userinserts the patch 40 into the receiving portion 110, as described inmore detail below.

The patch 40 includes an active reservoir 41, usually containing drugions in a gel, and a return reservoir 43, usually containing anelectrolytic gel, into which are placed the anode 42 and cathode 44. Theplacement of the anode 42 or the cathode 44 into the active reservoirdepends on the polarity of the drug ions, as is known in theiontophoretic art. Electrical interconnectors, such as wires or circuittraces 46 and 47, respectively connect the anode 42 and cathode 44 tothe current source of the controller, through terminals 60 and 61, whenthe patch is inserted into the controller.

The patch 40 also includes a backing layer 39 and an interconnection tab50. The backing layer 39 and tab 50 are made of a sturdy, dielectric,flexible material such as plastic or the like. This material may also bepermanently deformable. The tab 50 has an opening 30, such as a narrowslot, for engaging the lower protruding member 10 of the receivingportion 110 when patch 40 is inserted into the controller 20. Theopening 30 may be formed in any number of different shapes including,but not limited to, oval, circular, triangular or square shapes, so longas the opening 30 engages onto the lower protruding member 10 when thepatch is inserted into the controller, and the patch is held securelyinto place with a minimum of movement thereafter.

The patch 40 is connected to the controller 20 by inserting theinterconnection tab 50 into the receiving portion 110 of the controller20. As an end portion 45 of the interconnection tab 50 slides over thelower protruding member 10, resistance to insertion of the tab 50 of thepatch 40 increases, thus providing tactile feedback to the user. A mild"snap" is also preferably felt by the user as the opening 30 fullyengages and locks onto the lower protruding member 10.

This arrangement relies on the natural resilience of the patch tabmaterial to act as a spring as long as the material is not overstressed.When the patch is removed, the patch tab material becomes overstressedand the patch tab is deformed permanently, such that the opening 30 canno longer securely engage the lower protruding member 10 uponreinsertion of the patch into the controller, thus preventing reuse ofthe patch after removal, as described in more detail below.

Moreover, this arrangement firmly locks the patch 40 into the receivingportion 110 of the controller 20, ensuring that the patch 40 cannot beeasily removed from the controller 20 through inadvertence by a slightpulling of the interconnection tab 50, thereby providing a securemechanical and electrical connection. This feature also advantageouslyprevents the inadvertent insertion of a patch into the controller 20.

In a second embodiment of the present invention, illustrated in FIGS. 2,3A-B and 5B, an upper protruding member, located on one side or theother of the lower protruding member 10, is provided. The upperprotruding member may slant angularly, in a ramping fashion, so as todescend downwardly from the upper surface 22 of the receiving portion110. As shown in these figures, two upper protruding members 72 and 74are provided, one on each side of the lower protruding member 10. Theaddition of these upper protruding members to the receiving portion 110greatly enhances the tactile feedback and "snap" felt by the user wheninserting tab 50 of the patch 40 into receiving portion 110 of thecontroller 20.

In a third embodiment of the present invention, the patch 40 is removedfrom the receiving portion 110 of the controller 20 by squeezing sides55 and 56 of the tab 50 toward each other. In this embodiment, the tabis preferably made of a material that permanently deforms when squeezed.As illustrated in FIGS. 4 and 5A-B, the inward force of the squeezingmotion, depicted by arrows A, causes the tab 50 to bulge upwardly(toward direction B) in its center, allowing the opening 30 to rise upabove and disengage the protruding member 10 (to illustrate thesqueezing action more clearly, only a cut-away of the inserted portionof tab 50 is shown in the FIG. 6.

At that time, the tab 50 is then pulled outwardly, in the directionindicated by arrow D, from the receiving portion 110, resulting in theelectrical and mechanical disconnection of the patch 40 from thecontroller 20. The action of squeezing together sides 55 and 56 of thetab 50 deforms the tab material so as to disfigure permanently the tab50 into the shape as shown by the cross-section in FIG. 4. Thisdisfigurement prevents the patch 40 from reconnecting to the controller20 because the disfigured tab 50 cannot interlock with the protrudingmember 10. Thus, the use of the patch is prevented.

In a fourth embodiment of the present invention, illustrated in FIGS. 6and 7, a cutting edge 90 forms the rear edge of the lower protrudingmember 10. When the tab 50 is pulled out from the receiving portion 110of the controller 20, the opening 30 of the tab 50 is, sliced open intoat least two pieces, permanently disfiguring the tab. The cutting edge90 may take any shape, but the sharper the edge, the less force will berequired to remove and cut the patch. The cutting edge 90 may be locatedin any area of the receiving portion 110, so long as it causes thepermanent disfigurement of the tab 50 when the tab 50 is removed.

In this embodiment, it is not necessary to squeeze the tab 50 inward toremove the tab. The user simply pulls on the patch 40 or tab 50outwardly from the controller 20, causing the portion of the opening 30nearest the electrical terminals 60 and 61 to contact the cutting edge90. As more pulling force is applied, the cutting edge 90 begins toslice the tab 50 at the leading portion 120 of the opening 30. Thecutting edge continues to slice the tab 50 until it is cut into twoportions, from the front of the opening 30 to the end portion 45 of thetab 50. The tab 50, and thus the patch 40, is permanently disfigured andcannot be reinserted into the controller 20.

Moreover, the tab 50 may be designed so that when cutting edge slicesthrough the tab it slices through one or more of the patch electricalconnections, for example, connections 46 and 47. This last featureprevents an electrical connection between the patch and the controllereven if an otherwise disfigured patch is forcibly reinserted back intothe controller for attempted reuse. Without an electrical connection, nocurrent can pass through the patch electrodes, and no iontophoresis canoccur.

Thus, the present invention provides a new and useful iontophoreticsystem that (1) provides the user with tactile feedback and "snap" forrespectively determining whether a patch is being properly inserted intoand connected with a controller, (2) provides a secure a mechanical andelectrical connection between the patch and the controller, and (3)prevents the reuse of previously-used patches by disfiguring them, invarious ways, upon their removal from the controller.

Of course, it will be appreciated that the invention may take formsother than those specifically described, and the scope of the inventionis to be determined solely by the following claims.

What is claimed is:
 1. An iontophoretic system comprising:a currentcontroller having an energy source, current regulation circuitry and apatch-receiving portion including an upper surface and a lower surface,and a first member protruding from said lower surface in a ramp-likefashion toward said upper surface and terminating in a top edge nearsaid upper surface; a patch having an interconnection tab including anopening for engaging said first member when said interconnection tab isinserted into said patch-receiving portion of said current controllerand said opening falls over said top edge of said first member; anactive reservoir; a first electrode in the active reservoir; anelectrical interconnector connecting the first electrode to currentcontroller; a return reservoir; a second electrode in the returnreservoir; and an electrical interconnector connecting the secondelectrode to the current controller.
 2. The iontophoretic systemaccording to claim 1, wherein said current controller further comprisesa second member descending from said upper surface in a ramp-likefashion toward said lower surface and terminating in a bottom edge nearsaid lower surface.
 3. The iontophoretic system according to claim 1,wherein said current controller further comprises a plurality of secondmembers, each second member descending from said upper surface in aramp-like fashion toward said lower surface and terminating in a bottomedge near said lower surface, said second members located on each sideof said first member.
 4. The iontophoretic system according to claim 1,wherein said interconnection tab permanently deforms when apredetermined amount of force is applied to said interconnection tab todisengage said opening of said interconnection tab from said firstmember.
 5. The iontophoretic system according to claim 1, wherein saidfirst member of said current controller disfigures said interconnectiontab of said patch upon removing said interconnection tab from saidreceiving portion.
 6. The iontophoretic system according to claim 5,wherein the disfigurement of said interconnection tab comprises slicingthrough said opening of said interconnection tab.
 7. The iontophoreticsystem according to claim 5, wherein said interconnection tab has aplurality of electrical connections to electrically connect said patchwith said current controller, and the disfigurement of saidinterconnection tab comprises slicing through at least one of saidelectrical connections.
 8. The iontophoretic system according to claim1, wherein said first member of said current controller has a rearcutting edge.
 9. A method for rendering an iontophoretic patch having aninterconnection tab unreusable, said method comprising the stepsof:inserting the interconnection tab into a patch-receiving portion of acurrent controller so an opening of the interconnection tab engages amember protruding from the patch-receiving portion of the currentcontroller; and applying a predetermined amount of force to the sides ofthe interconnection tab to disengage the opening of the interconnectiontab from the protruding member so as to permanently deform theinterconnection tab.
 10. A method for rendering an iontophoretic patchhaving an interconnection tab unreusable, said method comprising thesteps of:inserting the interconnection tab into a patch-receivingportion of a current controller so an opening of the interconnection tabengages a member protruding from the patch-receiving portion of thecurrent controller; and pulling the interconnection tab out from thepatch-receiving portion so as to permanently disfigure theinterconnection tab.
 11. A method according to claim 10, wherein theprotruding member has a rear cutting edge, and in the pulling step, theinterconnection tab is pulled through the rear cutting edge.